Hydration Calculator
Use this tool to estimate a practical daily hydration target based on your body size, activity, heat exposure, and life stage. It gives you a flexible starting point so you can support energy, training, and recovery without turning water into another rigid rule.
Your Inputs
Your Results
Daily Drinking Water Target
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In Liters
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Body Size Baseline
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Your starting point before activity and environment are added.
Exercise Add-On
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Extra fluid for sweat losses during movement.
Heat / Life Stage Adjustment
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This accounts for warmer weather and major physiological demands.
Pick your inputs and calculate to see your hydration target.
This calculator estimates drinking water needs, not total water from food plus beverages. Your real needs can rise with sweat rate, heat, altitude, illness, and training demands. If your urine is consistently very dark, you feel dizzy, or you have a medical condition affecting fluid balance, get personalized guidance.